Airglow as an Indicator of Upper Atmospheric Structure and Dynamics

Airglow as an Indicator of Upper Atmospheric Structure and DynamicsGaseousenvelopesofplanetshavelongbeenthe objectof astrophysicalspectrop- tometric investigations into the processes proceeding in these remote objects of the solar system. However,only the Earth’s atmospheresurroundingus givesthe widest opportunities for a more detailed investigation of its properties. As a rule, the study of these properties is considered as a purely geophysical problem, but in fact they are a special case of the general astronomical phenomenon. Over the past more than half-century, atmospheric physics has become engaged in the research of the entire gaseous medium surrounding our planet extending to the interplanetary space. Despite the subdivision of the atmosphere into separate moreor less homogeneousaltitude layers studiedseparatelyfromother atmospheric regions,theselayersareininteraction,whichis manifestedsometimesunexpectedly for the researches of conventionalproblems. Of course, solar radiation whose effect in each particular case is determined by vertical pro les of gaseous atmospheric constituents and by their absorbing and scattering properties unites all these regions of the atmosphere into a single whole. TheabsorbedenergyoftheSuncreatesa certainthermalregimeineachregionof the atmosphere whose response is emissions arising from molecules or atoms c- tained in this region. These two processes participate in the establishment of th- mal equilibrium in the atmosphere. The atmospheric airglow spectrum is extremely wide; it is determined by the atmospheric conditions, including photochemicalp- cesses characteristic of individual altitude layers. This allows atmospheric airglow to be used as a very informative indicator for atmospheric remote sounding.

An up-to-date review of upper atmosphere airglow research providing a modern approach to understanding the formation and characterisation of upper atmospheric airglow emissions